The present invention relates to rotary regenerative heat exchangers and more particularly to the rotor housing and the housing support.
A rotary regenerative heat exchanger, conventionally used as an air preheater for combustion equipment, is composed of a rotor, containing heat exchange surface, which is usually mounted on a vertical shaft for rotation within a heat exchanger housing which surrounds the rotor. Extending across the heat exchanger on the lower end below the housing, normally the cold end, is a cold end center section which serves as a support for the entire heat exchanger structure including the rotor. Extending across the top of the heat exchanger, above the housing and parallel to the cold end center section, is a hot end center section. This hot end center section functions as the mounting means for the upper end of the rotor shaft. The hot end center section is supported by main support pedestals on each end of the hot end center section which are, in turn, supported on the ends of the cold end center section.
The conventional housing for large air preheaters comprises a plurality of housing panels arranged around the periphery of the rotor. See U.S. Pat. Nos. 5,655,594 and 5,628,360. Typically there are eight or more sides. Mounted on the inside of each housing panel between the panels and the rotor are arch-shaped stiffeners which cooperate to form a close fitting circular flange around the rotor. Conventional bypass sealing means are provided between the rotor and these archshaped stiffeners to prevent the by-pass of air or flue gas around the outside of the rotor.
Attached to each end of the heat exchanger housing are the air and gas connecting plate duct assemblies. These are connections which make the transition between the duct work, which is usually rectangular, and the generally circular heat exchanger and are attached to the sides of the hot and cold center sections. The housing panels are attached to and between these connecting plate duct assemblies thereby forming the housing. The housing panels are structural members of the overall air preheater framework and are somewhat complicated structures and thus shop assembled.